Hidrotermična separacija vrednih spojin iz bele omele (Viscum album)

magistrsko delo

Anej Pevec (Author), Mojca Škerget (Mentor), Maja Čolnik (Co-mentor)

Abstract

V magistrskem delu je predstavljena učinkovitost hidrotermične ekstrakcije pri podkritičnih pogojih za separacijo vrednih spojin iz bele omele (Viscum album), ki, kot parazitska rastlina, predstavlja odpadno biomaso. Preučili smo vpliv procesnih parametrov: temperature (100, 125, 150 in 180 °C), razmerja med materialom in topilom (1:10 ter 1:5) in časa ekstrakcije (10, 30 in 60 minut) na izkoristek ekstrakcije, sestavo in aktivnost ekstrakta. Najvišji izkoristek ekstrakcije smo dosegli pri pogojih 150 °C, trajanju 60 minut in razmerju 1:10, kjer je znašal 46,73 %. Dokazali smo, da imajo vsi ekstrakti bele omele antioksidativno aktivnost. Najvišja antioksidativnst (34,32 %) je bila izmerjena pri ekstraktu pri razmerju 1:5, temperaturi 125 °C in času 60 minut. Ugotovili smo, da ima temperatura ključno vlogo pri ohranjanju protivnetne aktivnosti rastlinskih ekstraktov. Najvišjo protivnetno aktivnost so dosegli ekstrakti, pridobljeni pri 100 °C (od 77,79 % do 88,70 %), ne glede na razmerje med materialom in vodo, pri čemer je bila aktivnost stabilna tudi ob daljši ekstrakciji. Vsebnost celokupnih fenolov v ekstraktih je bila močno odvisna od temperature, časa ekstrakcije in razmerja material:voda. Pri razmerju 1:10 je bil najvišji izkoristek (4,1 mg GA/g) dosežen pri 150 °C in 60 minutah. Pri krajših časih in višjih temperaturah pa je bila vsebnost nižja zaradi možne toplotne degradacije. Vsebnost celokupnih flavonoidov v ekstraktih je bila močno odvisna od temperature in časa ekstrakcije. Pri razmerju 1:10 je bil najvišji izkoristek (3,4 mg QU/g) dosežen pri 150 °C po 60 minutah. Krajši časi pri višjih temperaturah so pokazali nižjo vsebnost (od do), kar nakazuje na možno toplotno degradacijo spojin. Določevali smo tudi antihiperglikemično aktivnost pri ekstraktih, ki so pri razmerju 1:5 pokazali visoko stopnjo aktivnosti. Najvišjo antihiperglikemično aktivnost smo dosegli pri razmerju 1:5, procesnimi pogoji 150 °C ter 60 min, in je znašala 81,81 %. S HPLC analizo smo ugotavljali prisotnost določenih fenolnih spojin v ekstraktih. Ugotovili smo prisotnost petih pomembnih fenolnih spojin (klorogenske kisline, kofeinske kisline, epikatehina, epigalokatehin galata in galne kisline) ter kofeina in prišli do zaključka, da je dvostopenjska ekstrakcija (kjer smo material predhodno obdelali s CO2) v tem primeru kazala manjšo prisotnost komponent, kar je kazalo na toplotno občutljivost fenolnih spojin. Z ekstrakcijo z nadkritičnim CO2 smo ekstrahirali proste maščobne kisline in olja. V ekstraktih smo zasledili palmitinsko kislino, linolejsko kislino, oleinsko kislino in druge. Ugotovili smo, da dvostopenjska ekstrakcija omogoča boljši izkoristek pri nadaljnji ekstrakciji s podkritično vodo, zlasti pri razmerju 1:10, kjer se kaže visoka protivnetna aktivnost. Kljub temu se pri višjih temperaturah in daljšem času učinkovitost zmanjša zaradi degradacije spojin. Pri razmerju 1:5 dvostopenjska metoda izboljša protivnetne, ne pa tudi antihiperglikemične aktivnosti ekstraktov.

Keywords

bela omela;ekstrakcija;podkritična voda;nadkritični CO2;bioaktivne komponente;magistrske naloge;

Data

Language:	Slovenian
Year of publishing:	2025
Typology:	2.09 - Master's Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[A. Pevec]
UDC:	66.061.3:582.728.22(043.2)
COBISS:	236085507
Views:	0
Downloads:	8
Average score:	0 (0 votes)
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Other data

Secondary language:	English
Secondary title:	Hydrothermal separation of valuable compounds from mistletoe (Viscum album)
Secondary abstract:	This MSc thesis presents the efficiency of hydrothermal extraction under subcritical conditions for the separation of compounds of interest from white mistletoe (Viscum album), which, as a parasitic plant, represents waste biomass. The influence of the process parameters: temperature (100, 125, 150 and 180 °C), material/solvent ratio (1:10 and 1:5) and extraction time (10, 30 and 60 min); on the extraction yield, composition and activity of the extract was investigated. The highest extraction yield was obtained at 150 °C, 60 min and 1:10 ratio, where it was 46.73 %. We have shown that all white mistletoe extracts have antioxidant activity. The highest antioxidant activity (34.32 %) was measured for the extract at 1:5, 125 °C and 60 min. We found that temperature plays a key role in maintaining the anti-inflammatory activity of plant extracts. The highest anti-inflammatory activity was obtained with extracts extracted at 100 °C (from 77.79 % to 88.70 %), irrespective of the material/water ratio, and the activity was stable even with longer extraction times. The total phenolic content of the extracts was strongly dependent on temperature, extraction time and material:water ratio. At a ratio of 1:10, the highest yield (4.1 mg GA/g) was obtained at 150 °C and 60 minutes. However, shorter times and higher temperatures resulted in lower yields due to possible thermal degradation. The total flavonoid content of the extracts was strongly dependent on the extraction temperature and time. At a 1:10 ratio, the highest yield (3.4 mg QU/g) was obtained at 150 °C after 60 minutes. Shorter times at higher temperatures showed lower contents (from to), indicating possible thermal degradation of the compounds. Antihyperglycaemic activity was also determined for the extracts, which showed, at a 1:5 ratio, a high level of activity. The highest antihyperglycaemic activity, 81.81 %, was obtained at a 1:5 ratio, 150 °C and 60 min. The presence of certain phenolic compounds in the extracts was determined by HPLC analysis. The presence of five important phenolic compounds (chlorogenic acid, caffeic acid, epicatechin, epigallocatechin gallate and gallic acid) and caffeine was detected and it was concluded that the two-step extraction (where the material was pre-treated with CO2) in this case showed a lower presence of the components, which was indicative of the heat sensitivity of the phenolic compounds. Free fatty acids and oils were extracted by supercriticalCO2 extraction. Palmitic acid, linoleic acid, oleic acid and others were found in the extracts. We found that the two-stage extraction gives a better yield when further extracted with subcritical water, especially at a ratio of 1:10, where a high anti-inflammatory activity is shown. However, at higher temperatures and longer times, the efficiency decreases due to degradation of the compounds. At 1:5, the two-step method improves anti-inflammatory but not antihyperglycaemic activity of the extracts.
Secondary keywords:	white mistletoe;extraction;subcritical water;supercritical CO2;bioactive components;
Type (COBISS):	Master's thesis/paper
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	1 spletni vir (1 datoteka PDF (XIII, 62 str.))
ID:	26212696